Centrifugal pump

ABSTRACT

A centrifugal pump has a housing and an impeller rotatable therein which has a coaxial inlet, and there are a plurality of pumping passages extending from said inlet to the periphery of the impeller, each passage having end walls or vanes radiating outwardly from said inlet and spaced opposed side walls which have undulated surfaces such that the stream of fluid in each passage is repeatedly richocheted or deflected by the undulations of one surface to the undulations of the other surface in directions that are inclined to a diametral plane of the impeller and toward the periphery, as the fluid is centrifugally impelled through the passage, whereby to produce a high degree of vacuum with a relatively small impeller. Preferably portions of said undulated surfaces are curved to form said vanes and to enhance smooth flow of liquids and reduce the possibility of clogging by solids or fibers therein.

United States Patent 1191 1111 3,907,456 Krienke Sept. 23, 1975 [5 CENTRIFUGAL PUMP 13,852 1914 United Kingdom 4l5/76 8 l 19 I F 4 7 [76] Inventor: Heinz Herbert Krienke, 1130 9 3 5O 2/ 5 6 gf ggg Plamfield Primary Examiner-Henry F. Raduazo Attorney, Agent, or Firm-Harry B. Rook [22] Filed: Nov. 18, 1971 21 Appl. No.: 200,106 [57] ABSTRACT A centrifugaLpump has a housing and an impeller ro- Related Apphcat'on Data tatable therein which has a coaxial inlet, and there are Continuation-impart 0f y a plurality of pumping passages extending from said l9701aba'1dnedinlet to the periphery of the impeller, each passage having end walls or vanes radiating outwardly from U-S- R aid inlet and paced pposed ide walls have [51] Int. Cl. ..F04D1/04 undulated Surfaces such that the Stream f fl id in [58] Field of Search 415/76 500, 90; 416/186, each passage is repeatedly richocheted or deflected by 416/179 the undulations of one surface to the undulations of the other surface in directions that are inclined to a References Clted diametral plane of the impeller and toward the periph- UNITED STATES PATENTS ery, as the fluid is centrifugally impelled through the l,0l3,248 1/1912 Wilkinson 415 90 Passage, whereby to Produce a high degree of vacuum 1,383,937 7/1921 G h i 415/76 with a relatively small impeller. Preferably portions of 2,737,898 3/1956 Andermattetal. 415/76 said undulated surfaces are curved to form said vanes 2,780,176 2/1957 Holzwarth 416/186 and to enhance smooth flow of liquids and reduce the FOREIGN PATENTS OR APPLICATIONS possibility of clogging by solids or fibers therein.

45 2/l914 United Kingdom 415/76 11 Claims, 12 Drawing Figures -1: Z 5 l 3 fi H j Z B 1 l I 5 I /.3-

I a f F/ v /0 7 US Patent Sept. 23,1975 Sheet 1 of3 3,907,456

I N VENTQR e/Z 1%: 07/66,

HHer'Z US Patent Sept. 23,1975

Sheet 2 of 3 Z6 INVEINIITOR H. Herberz Knew/ 6 BY %7 HTT RNEY US Patsnt Sept. 23,1975 Sheet 3 of3 3,907,456

ATTORNEY CENTRIFUGAL PUMP This is a continuation-in-part of my copending application Ser. No. 40773, filed May 27, 1970 now abandoned.

BACKGROUND OF THE INVENTION 1. The Field of the Invention:

The invention relates to centrifugal pumps of the type that includes an impeller or rotor having a central or coaxial inlet and a plurality of circumferentially spaced pumping passages leading from said inlet through outlets at the periphery of the impeller and defined by spaced opposed side walls and end walls radiating outwardly from said inlet to said periphery.

2. The Prior Art:

In the early prior art pumps, the side walls of the pumping passages are smooth and planar from the inlet to the outlet.

Later developments in the art produced pumps having pumping passages between frusto-conical shells with a reversal of flow from the inlet to the passages, for the specific purpose of preventing vaporization of the liquid being pumped, for example as shown in US. Pat. No. 2,569,563.

A still later pump has pumping chambers formed with grooves in their side walls shaped and arranged in a special way to produce a pumping action for a mixture of liquid and gas which will prevent separation and accumulation of the gas in the pumping chamber, as shown in US. Pat. No. 2,737,898.

The prior art pumps leave much to be desired in that 'they are not capable of operating with a sufficiently high degree of vacuum.

SUMMARY A primary object of the invention is to provide a centrifugal pump which will operate with a higher degree of vacuum than known centrifugal pumps.

The invention also provides a centrifugal pump which will produce a given suction and dynamic head with a smaller impeller than is possible with pumps of conventional design.

It is another object of the invention to provide in a centrifugal pump, a novel and improved impeller whereby a given degree of vacuum can be produced with an exceptionally efficient use of power.

For accomplishing these and other objects which will later appear, the invention especially contemplates a centrifugal pump having novel and improved pumping passages wherein the fluid being pumped is caused in its travel from the inlet to the outlet to frictionally contact successively surfaces on the side walls of the passages which on each side wall are disposed transversely of the fluid flow and are inclined to a diametral plane of the impeller alternately in different directions with each surface on one side wall spaced from and opposed to a surface on the other side wall and inclined in the same direction.

The total of the areas of the undulations or angularly related surfaces produce a wavy path of travel for the liquid greater than the area of the flat, smooth surfaces in the pumping passages of conventional pumps, so that when compared with such conventional pumps, each passage has a longer path of travel for the fluid and consequent increase in period and area of frictional contact of the fluid with the passage walls, whereby the velocity of the fluid and the total dynamic head are increased.

In accordance with the invention, the radiating end walls of the pumping passages are provided by vanes which are approximately radial to the impeller and into which said undulated surfaces merge through curved portions to provide for smooth flow of liquids and to prevent clogging of the pump by solids or fibers, for example, sand, wood, pulp, etc.,

BRIEF DESCRIPTION OF THE DRAWINGS For a more complete understanding of the invention, reference should be had to the following description in conjunction with the accompanyingdrawings in which:

FIG. 1 is a schematic central vertical sectional view of a pump embodying the present invention, taken approximately on the plane of the line 11 of FIG. 2;

FIG. 1A is an enlarged view of the portion of FIG. 1 that is encircled by light dot and dash lines in FIG. 1;

FIG. 2 is a transverse vertical sectional view approximately on the plane of the line 22 of FIG. 1;

FIG. 3 is a fragmentary schematic sectional view of a modified form of the invention;

FIG. 4 is a similar view of another form of the invention;

FIG. 5 is a fragmentary central vertical sectional view through a centrifugal pump embodying another modification of the invention;

FIG. 6 is a view similar to FIG. 4 of another modification;

FIG. 7 is a fragmentary central vertical sectional view similar to FIG. 1, showing another form of the invention.

FIG. 8 is a view similar to FIG. 2 showing a modifica-' tion of the invention;

FIG. 9 is an enlarged fragmentary transverse vertical sectional view on the plane of the line 99 of FIG. 8;

FIG. 10 is a sectional view approximately on the plane of the line l0l0 of FIG. 8, and

FIG. 11 is a greatly enlarged fragmentary sectional view approximately on the plane of the line ll1l of FIG. 8.

DESCRIPTION OF THE PREFERRED EMBODIMENTS Specifically describing the embodiment of the invention shown in FIGS. 1, 1A and 2, the reference character A designates the housing of the pump which includes a main section 1 and an end plate 2 separably secured to the main section by cap screws 3 so as to provide between the sections a pumping chamber C. Impeller B is journaled to rotate within said housing chamber by means of a drive shaft 5 on which is a bushing 6 journaled in a packed bearing 7 having a gland 8 of generally known construction. The impeller is keyed on the shaft and the shaft is driven by any suitable source of power not shown so as to rotate the impeller at high speed.

The end plate 2 has an inlet conduit 9 provided with suitable means such as a flange 10 for connection to a fluid supply line, and the conduit leads to the inlet opening 12 of the impeller from which radiate a plurality of pumping passages D that are spaced circumferentially of the impeller and extend outwardly from the inlet opening to the outer periphery of the impeller where the passages discharge the fluid therefrom into an outlet conduit E of generally known construction formed in the main section of the housing. Each passage has end walls which are shown in the form of vanes 13 that radiate outwardly from the inlet opening as shown in FIGS. 1 and 2.

Each passage also includes side walls each of which has an undulated surface in spaced opposed relation to the undulated surface of the other side wall for causing the stream of fluid in each passage to be repeatedly ricocheted or deflected by the undulations of one surface to the undulations of the other surface in directions toward the outer periphery of the impeller and inclined to a diametral plane of the impeller which is perpendicular to the axis and may be represented by the clot and dash line in FIG. 1.

In the form of the invention shown in FIGS. 1, 1A and 2, one side wall of each passage is formed by the inner side of the end plate 2, while the other side wall of each passage is formed by the end of the impeller that is juxtaposed to the end plate; and the vanes 13 which form the end walls of the passage, are carried by the impeller.

Each undulated surface is shown as including a plurality of approximately concentric alternate ridges and grooves 14 and 15, respectively, spaced radially of the impeller between the adjacent end walls with the surfaces of the ridges of one side wall in spaced opposed relation of the surfaces of the grooves of the other side wall. As most clearly shown in FIG. 1A, each surface 16 of one side wall is in spaced opposed relation to a surface 17 of the other side wall; and the adjacent surfaces of each side wall meet each other to form the ridges and grooves and are inclined to said diametral plane or to the axis of the impeller in opposite directions, respectively.

The edges of the vanes are undulated or provided with alternate ridges and grooves corresponding to the undulations or ribs and grooves of the end plate or impeller, and it is desirable that there be a minimum of clearance between the edges of the vanes and the surfaces of the end plate adequate to permit free rotation of the impeller without frictional engagement of the impeller with the end plate. In both FIGS. 1 and 1A this clearance which is generally designated F is exaggerated for clearness in illustration, but it has been found that the pump will operate with different amounts of clearance. It is also desirable that the ridges of each side wall be disposed in what may be termed meshing relation with the opposite side walls. In other words, preferably each ridge of one side wall partially enters a groove in the opposite side wall as most clearly shown in FIG. 1A.

In the form of the invention shown in FIGS. 1 and 1A, the opposed surfaces of the two side walls are equidistantly spaced from each other, and the surfaces nearer the inlet opening are spaced apart the same distance as the surfaces adjacent the periphery of the impeller; but the invention also contemplates, as shown in FIG. 3, that the portions of the undulated surfaces 18 and 19 of the impeller G and end plate H, respectively, nearer the inlet opening 20 may be more distantly spaced apart than the portions adjacent the outer periphery of the impeller.

The invention also contemplates undulated surfaces of different shapes. For example, as shown in FIG. 4 the undulated surfaces 21 and 22 of the impeller l and end plate J, respectively, may be sinuous or curved.

In FIG. 1 the general planes of the undulated surfaces are parallel to a diametral plane and perpendicular to the axis of the impeller, but as shown in FIG. 6 the general planes of the undulated surfaces 23 and 24 of the impeller K and end plate L, respectively, are frustoconical and inclined to the axis of the shaft.

The invention also contemplates a pump having a plurality of series of pumping passages spaced longitudinally of the axis of the shaft, as shown, for example in FIG. 7. Here the impeller M is rigidly mounted on a shaft 25 which is journaled in one end plate 26 of the pump housing N. The housing includes another end plate 0 and the impeller is located between these two end plates and between the inner side of each end plate and one end of the impeller is one series of pumping passages P, while between the inner side of the other end plate 0 and the adjacent end of the impeller M is a second series of pumping passages Q. The inner ends of all the passages communicate with the inlet opening 27 and extend outwardly from said inlet opening to the outer periphery of the impeller where the passages discharge into an outlet conduit R which may be of the same general form as the conduit E. As shown in FIG. 7 each passage has end walls formed by vanes 28 and side walls having undulated surfaces of the same general form as the vanes and side walls shown in FIG. 1.

FIG. 5 shows another form of the invention where the impeller S comprises one block rigidly mounted on a shaft 29 journaled in a bearing 30 in one end of housing T the other end of which has an inlet conduit 31 coaxially disposed with which is inlet opening 32 of the impeller. Leading outwardly from said inlet opening is a plurality of pumping passages U having end walls or vanes 33 radiating outwardly from the inlet opening and side walls 34 and 35 each of which has an undulated surface in spaced opposed relation to the undulated surface of the other side wall. The passages extending from the inlet 32 to the periphery of the impeller and discharge into an outlet conduit (not shown) but similar to that illustrated in FIG. 1.

It will be understood by those skilled in the art that the form of the vanes may be varied in number and form; for example, they may be of volute or curved form as shown or may be straight and truly radial to the impeller, and in all forms of the invention, when the inlet conduit is connected to the fluid supply and the impeller or rotor is rotated at high speed the fluid, usually liquid, will be impelled centrifug ally from the inlet opening through the pumping passages to the outlet conduit.

In accordance with the invention, the total areas of the undulations or angularly related surfaces in the side walls of the pumping passages produces a wavy path of travel for the liquid greater than the area of the generally flat and smooth surfaces in pumping passages of conventional pumps. When compared with conventional pumps, the invention provides in each passage a longer path of travel for the fluid and consequent increases in area of frictional contact of the fluid with the passage walls, whereby the velocity of the fluid and the total dynamic head are increased by the pump of the invention.

FIGS. 8 through 11 illustrate a modification of the invention wherein the radiating end walls of the pumping passages are shown as approximately radial to the impeller and the undulated surfaces or the sides of the alternate concentric ridges and grooves merge into the end walls through curved portions to provide for smooth flow of liquids throughthe pumping passages and to reduce the possibility of'clog'ging ofthe pumpby solid particles or fibers. 1

In this form of .the invention and referring to FIGS. 8-11, the pump housing is designated AA and the impeller is designated BB. The end plate of the housing (FIG. 9) is in general similar to the end plate 2 in the form of the invention hereinbefore described and includes the alternate ridges and grooves 21 and 22, respectively, which form the plurality of concentric surfaces spaced radially of the impeller with the surfaces of the ridges of the end plate in spaced opposed relation to the surfaces of the groove 23 and ridges 24, respectively of the impeller.

The end walls of the pumping passages are formed by the vanes 25 which in the present instance are shown as disposed radially of the face of the impeller, but which may be curved as in FIG. 2 and the sides of the vanes merge through curved surfaces 26 into the undulated surfaces or sides of the ridges 24 and grooves 23. While the vanes are shown to gradually decrease in width from the outer periphery of the impeller toward the center thereof as best illustrated in FIG. 8 and by the dotted lines in FIG. 11, this is not necessary in all cases; the vanes can be of the same width through their length.

With this construction, the pump operates in generally the same way as hereinbefore described, but the curved sides 26 of the vanes reduce the possibility of clogging of the pump by solids or fibers, for example sand,wood, pulp, etc., and said curved surfaces also provide for a smooth flow of the fluids through the pumping passages and over the undulated surfaces of the face of the impeller and the end plate.

It is believed that the pump operates with partially controlled cavitation which makes possible the production of a high degree of vacuum with a minimum of cavitation damage to the juxtaposed surfaces of the pumping passages. Bubbles are formed between the undulated surfaces in low pressure areas and decrease in size as they pass from one inclined surface to the next greater pressure area, and gas or vapor appears to collect in the pockets formed at the bottoms of the grooves, providing a layer of gas or vapor along which the fluid flows under the influence of the vanes 13; and in some cases it may be desirable to provide curved or small flat surfaces at the crests of the ridges on the vanes, for example as shown in FIG. 9 where the flat surfaces on the crests are denoted 27 on the ridges of the vanes 25 so that said crests will cause minimum disturbance of the gas or vapor pockets in the juxtaposed grooves 22 of the end plate 20. It will be understood that similar flat or rounded surfaces may be provided on the ridges of the vanes shown for example in FIGS. 1, la and 2.

I claim:

1. A centrifugal pump comprising a housing having an inlet conduit, an impeller journaled to rotate in said housing coaxially with said inlet conduit and having an inlet opening, and means including a drive shaft for driving said impeller, said housing also having an outlet conduit at the outer periphery of said impeller and there being a plurality of pumping passages spaced circumferentially of said impeller leading outwardly from said inlet opening through said outer periphery of the impeller, each passage having end walls radiating outwardly continuously from said inlet opening to the outer periphery of the impeller and side walls each of which has an undulated surface whose undulations are in spaced opposedrelation to the undulations of the undulated surface of the other side wall and inclined in the same directions to a diametral plane of the impeller for causing the stream of fluid in each passage to be repeatedly ricocheted or deflected by the undulations of one surface t0 the undulations of the other surface in directions toward said periphery of the impeller and inclined to a diametral plane of the impeller, as the fluid is centrifugally impelled through the passage.

2. A centrifugal pump as defined in claim 1 wherein each undulated surface includes a plurality of approximately concentric alternate ridges and grooves spaced radially of the impeller between the adjacent end walls with the surfaces of the ridges of one side wall in spaced opposed approximately parallel relation to the surfaces of the grooves of the other side wall.

3. A centrifugal pump as defined in claim 1, each side wall having a plurality of surfaces spaced radially of said impeller and approximately concentric therewith, each surface of one side wall being in spaced opposed relation to a surface in the other side wall approximately equidistantly throughout their widths and the adjacent surfaces of each side wall meeting each other and being inclined to a diametral plane of the impeller in opposite directions respectively.

4. A centrifugal pump as defined in claim 1 wherein said casing has an end plate in which said inlet conduit is located, and the inner side of said end plate and one end of said impeller are formed to provide said passages between them.

5. A centrifugal pump as defined in claim 1 wherein said casing has an end plate in which said inlet conduit is located, and the inner side of said end plate and one end of said impeller are formed to provide said passages between them, and each side wall has a plurality of surfaces spaced radially of the impeller and providing approximately concentric alternate ridges and grooves between the adjacent end walls with the surfaces of the ridges of one side wall in spaced opposed relation to the surfaces of the grooves of the other side wall.

6. A centrifugal pump as defined in claim 5 wherein said end walls comprise vanes on said impeller radiating outwardly from said inlet opening.

7. A centrifugal pump as defined in claim 1 wherein there are a plurality of series of said passages spaced apart axially of said drive shaft.

8. A centrifugal pump as defined in claim 1 wherein said housing has two end plates in which are located said inlet conduit and said shaft, respectively, and between which the impeller is disposed and the inner side of each end plate and the corresponding end of the impeller are formed to provide said passages between them.

9. A centrifugal pump as defined in claim 1 wherein said end walls of the passages comprise vanes radiating outwardly from said inlet opening.

10. A centrifugal pump as defined in claim 1 wherein said end walls of the passages comprise vanes radiating outwardly from said inlet opening and into which said undulated surfaces merge through curved portions providing for smooth flow of liquids and reducing the possibility of clogging of the pump by solid particles or fibers.

I relation to the surfaces of the grooves of the other side wall, and wherein said end walls of the passages comprise vanes radiating outwardly from said inlet opening and into which said undulated surfaces merge through curved portions providing for smooth flow of liquids and reducing the possibility of clogging of the pump by solid particles or fibers. 

1. A centrifugal pump comprising a housing having an inlet conduit, an impeller journaled to rotate in said housing coaxially with said inlet conduit and having an inlet opening, and means including a drive shaft for driving said impeller, said housing also having an outlet conduit at the outer periphery of said impeller and there being a plurality of pumping passages spaced circumferentially of said impeller leading outwardly from said inlet opening through said outer periphery of the impeller, each passage having end walls radiating outwardly continuously from said inlet opening to the outer periphery of the impeller and side walls each of which has an undulated surface whose undulations are in spaced opposed relation to the undulations of the undulated surface of the other side wall and inclined in the same directions to a diametral plane of the impeller for causing the stream of fluid in each passage to be repeatedly ricocheted or deflected by the undulations of one surface to the undulations of the other surface in directions toward said periphery of the impeller and inclined to a diametral plane of the impeller, as the fluid is centrifugally impelled through the passage.
 2. A centrifugal pump as defined in claim 1 wherein each undulated surface includes a plurality of approximately concentric alternate ridges and grooves spaced radially of the impeller between the adjacent end walls with the surfaces of the ridges of one side wall in spaced opposed approximately parallel relation to the surfaces of the grooves of the other side wall.
 3. A centrifugal pump as defined in claim 1, each side wall having a plurality of surfaces spaced radially of said impeller and approximately concentric therewith, each surface of one side wall being in spaced opposed relation to a surface in the other side wall approximately equidistantly throughout their widths and the adjacent surfaces of each side wall meeting each other and being inclined to a diametral plane of the impeller in opposite directions respectively.
 4. A centrifugal pump as defined in claim 1 wherein said casing has an end plate in which said inlet conduit is located, and the inner side of said end plate and one end of said impeller are formed to provide said passages between them.
 5. A centrifugal pump as defined in claim 1 wherein said casing has an end plate in which said inlet conduit is located, and the inner side of said end plate and one end of said impeller are formed to provide said passages between them, and each side wall has a plurality of surfaces spaced radially of the impeller and providing approximately concentric alternate ridges and grooves between the adjacent end walls with the surfaces of the ridges of one side wall in spaced opposed relation to the surfaces of the grooves of the other side wall.
 6. A centrifugal pump as defined in claim 5 wherein said end walls comprise vanes on said impeller radiating outwardly from said inlet opening.
 7. A centrifugal pump as defined in claim 1 wherein there are a plurality of series of said passages spaced apart axially of said drive shaft.
 8. A centrifugal pump as defined in claim 1 wherein said housing has two end plates in which are located said inlet conduit and said shaft, respectively, and between which the impeller is disposed and the inner side of each end plate and the corresponding end of the impeller are formed to provide said passages between them.
 9. A centrifugal pump as defined in claim 1 wherein said end walls of the passages comprise vanes radiating outwardly from said inlet opening.
 10. A centrifugal pump as defined in claim 1 wherein said end walls of the passages comprise vanes radiating outwardly from said inlet opening and into which said undulated surfaces merge through curved portions providing for smooth flow of liquids and reducing the possibility of clogging of the pump by solid particles or fibers.
 11. A centrifugal pump as defined in claim 1 wherein said casing has an end plate in which said inlet conduit is located, and the inner side of said end plate and one end of said impeller are formed to provide said passages between them, and each side wall has a plurality of surfaces spaced radially of the impeller and providing approximately concentric alternate ridges and grooves between the adjacent end walls with the surfaces of the ridges of one side wall in spaced opposed relation to the surfaces of the grooves of the other side wall, and wherein said end walls of the passages comprise vanes radiating outwardly from said inlet opening and into which said undulated surfaces merge through curved portions providing for smooth flow of liquids and reducing the possibility of clogging of the pump by solid particles or fibers. 